L Carnitine Promix Nutrition Will this make you smell like fish?! Pcos What is Carnitine? Carnitine in the crosshairs: A fishy tale? Dr. Ronald Hoffman Did You Know? Some people report a fishy smell after supplementing with L carnitine. This happens because certain gut bacteria convert carnitine to trimethylamine, a malodorous compound found in rotting fish. L Carnitine: Benefits, Uses, and Side Effects Lifespan Research Institute